Ramotswe Cousin Is Nice No. 2

The trouble with Isabel Dalhousie, protagonist of Alexander McCall Smith's latest novel, is not who she is but who she isn't.

She isn't Precious Ramotswe, the captivating star of Smith's popular ``No. 1 Ladies Detective Agency'' series. Perhaps it is not fair to compare them, yet Isabel is so much a regional variant of the sturdily built African detective that the comparison feels inevitable.

Isabel Dalhousie lives in Edinburgh, where she was born into a fair pile of money. Her parents are a Scottish lawyer and his American wife. She is a philosopher by education, temperament and trade, being the editor of the scholarly ``Review of Applied Ethics.'' She also totes some repressed baggage, which includes the heartache of a disastrous love affair and a bit of a crush on a much younger man.

As ``The Sunday Philosophy Club'' begins, Isabel sees a stranger plunge to his death from an upper balcony at the symphony. This disturbance in her placid routine spurs an impromptu investigation, which she pursues not so much to solve the puzzle as to reach its moral resolution.

As she pokes around Edinburgh, chatting up friends and associates of the young fund manager who took the mysterious, fatal fall, she tries to suppress recurring and colorful fantasies about the demise of Toby, her beloved niece's pompous new boyfriend. Isabel dislikes him with a ferocity that is constrained by her inflexible courtesy and her love for her niece, Cat. When she casually discovers a secret Toby has been hiding, she must decide whether it is right to tell Cat.

This devotion to ethics and morality -- as opposed to law and punishment -- is one of many traits Isabel shares with Smith's other heroine, Precious Ramotswe. Also, they both think a lot.

Isabel's inner dialogue is more restrained, delicate and abstract than Precious's forthright reasoning. When considering whether lies are morally permissible to protect someone from harm or to spare feelings, Isabel considers Kant's position on the matter and ends up with more questions than answers.

``If somebody asked one's opinion of a newly acquired -- but tasteless -- possession, for instance, and one gave an honest answer, then that could hurt feelings and deprive the other of the joy of ownership,'' she reflects. ``So one lied, and praised it, which was surely the right thing to do. Or was it?''

Some bracing contrast to her theorizing comes from her housekeeper, Grace, a blunt and unapologetic Scottish traditionalist with no uncertain views on many people and issues, especially the general decline of civilization. Manners, she opines, ``have gone right down the cludgie.'' Her conversations with her boss are among the book's most entertaining scenes.

Smith has once again succeeded brilliantly in constructing not only believable and engaging characters, but also a vivid and particular sense of place. His Edinburgh is restrained, conventional and cultured, plus rainy and a little bit sad.

Devotees of his five-book (so far) ``No. 1 Ladies Detective Agency'' series are certain to enjoy these new people and this new place. But they may feel the kind of guilt that comes with a preference for one child in a family over his or her sibling.

To know Precious Ramotswe is to love her. To know Isabel Dalhousie is to like and admire her. It's just not the same.

Alexander McCall Smith will talk about and sign copies of ``The Sunday Philosophy Club'' on Wednesday at 7 p.m. at Scranton Library, 801 Boston Post Road, Madison. A $2 donation to the library is suggested. The event is presented by R.J. Julia Booksellers of Madison. For a reservation or information, call the bookstore at 203-245-3959.